Due for completion at the end of April, the £11.6m Enterprise Centre on the University of East Anglia’s (UEA) Norwich campus aims to push the use of British timber on a large-scale – 3,400 sq m – project to its limits, writes Tom Ravenscroft.
Adapt Low Carbon Group, a UEA enterprise set up to promote low-carbon business practice, wanted to create an exemplar scheme as a catalyst for others to adopt bio-renewable materials. Architect Architype and contractor Morgan Sindall had to convince the supply chain to adapt to construct a building from local timber.
For Architype, timber was the natural option for designing a sustainable building, and to reduce embodied carbon sourcing locally was key. After reading a report by InCrops, a research team based at UEA, which highlighted the potential for local timber to be used as a structural building material, the architect set out not only to specify timber from the UK, but from East Anglia specifically.
“Using this untapped resource has the obvious benefit of reducing carbon, and could perhaps create an industry in the local area,” explains Ben Humphries, associate director at Architype.
As the local timber industry produces low-grade fencepost and pulp, there was no existing supply chain, so sourcing local wood was a challenge. First, the Forestry Commission had to be convinced of the potential benefits, then Cygnum, a timber-frame company, had to be persuaded to work with timber from outside its existing supply chain. Finally, Thomson Sawmills, a local timber mill, had to accept the loss of productivity caused by altering the mill’s usual set-up.
The result is that 70% of the building’s timber panels are constructed from Corsican pine, sourced from Thetford Forest, just 30 miles from site. However, as there is nowhere to grade this timber in the UK, it had to be sent to Ireland, where it was processed and the remainder of the material for the frame – Sitka spruce – was sourced.
“It’s still a massive success,” says Humphries. He acknowledges the embodied carbon of the building may have been lower if all the timber had come from Ireland, as it would have only travelled one way, but “proving locally grown timber from East Anglia, in this case Corsican pine, can be used structurally was equally important,” he says.
Suffolk Corsican pine and Irish Sitka spruce stud work, North American I-joists and Austrian glulam form part of the building’s structure
Local timber was also specified for other elements. Perhaps most importantly, the 7.5 metre signature columns that form the entrance canopy are constructed from glue-laminated larch, also from Suffolk.
“It was important to the project’s message to have this visual element sourced locally,” says Humphries.
Reclaimed oak from Norfolk forms much of the building’s cladding: African iroko recycled from the university’s chemistry department, where it was originally lab desks, is used on the front of the building.
However, not all of the timber could be sourced from East Anglia or, even Great Britain. The OSB was sourced from Ireland, as it was not economically feasible. Internal glulam beams that form part of the hybrid frame came from Austria, as buying locally would have been around 40% more costly.
As Humphries explains: “Value judgements had to be made.”
The I-beams for the first-floor and roof construction are also imported. The architect had wanted to use Scottish timber but this was not economically viable, so Polish timber was agreed. However, an unfortunate breakdown in communication led to the sub-contractor buying American timber from its usual supplier. For Architype this episode demonstrates the difficulty of deconstructing existing supply chains and the vigilance needed to specify sustainably.
But the Enterprise Centre shows that, with a dedicated client, architect, contractor and with local support, it is possible to construct large-scale projects with British timber.
The 7.5m high columns on the entrance canopy were constructed from glue-laminated larch from Suffolk
